Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Job Classification

In most duration tables, five job classifications are displayed. These job classifications are based on the amount of physical effort required to perform the work. The classifications correspond to the Strength Factor classifications described in the United States Department of Labor's Dictionary of Occupational Titles. The following definitions are quoted directly from that publication.

Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Hip Dysplasia


Related Terms

  • Congenital Hip Dislocation
  • DDH
  • Developmental Dysplasia of the Hip
  • Hip Dislocation
  • Hip Subluxation

Differential Diagnosis

Specialists

  • Family Physician
  • Orthopedic (Orthopaedic) Surgeon
  • Physiatrist (Physical Medicine and Rehabilitation Specialist)
  • Physical Therapist
  • Sports Medicine Physician

Comorbid Conditions

Factors Influencing Duration

Length of disability depends on the severity of the hip dysplasia, whether the condition is unilateral or bilateral, whether the condition is managed nonoperatively or operatively, the individual’s job requirements, and whether hip osteoarthritis is present concurrently.

Medical Codes

ICD-9-CM:
754.30 - Congenital Dislocation of Hip, Unilateral; Congenital Dislocation of Hip NOS
754.31 - Congenital Dislocation of Hip, Bilateral
754.32 - Congenital Subluxation of Hip, Unilateral; Congenital Flexion Deformity, Hip or Thigh; Predislocation Status of Hip at Birth; Preluxation of Hip, Congenital
754.33 - Congenital Subluxation of Hip, Bilateral
754.35 - Congenital Dislocation of One Hip with Subluxation of Other Hip

Overview

Hip dysplasia is a condition in which the hip joint, a synovial ball and socket joint (an enarthrosis), becomes unstable, typically because the bones and/or supportive soft tissues (joint capsule, ligaments) of the hip have developed or grown abnormally in utero. With hip dysplasia, the hip socket (acetabulum) usually is shallow and does not hold the ball (femoral head) securely; in addition, the femur may be abnormally twisted, causing increased forces at the hip joint. Over time, associated looseness (laxity) of support ligaments and pulling of hip muscles allows increased movement of the femoral head within the acetabulum, resulting in abnormal forces on the joint surfaces that cause joint instability, degeneration, and chronic pain.

With hip dysplasia, the surfaces of the hip joint (the femoral head, or "ball", and the acetabulum, or "socket") may experience incomplete contact (subluxation) or a total loss of joint contact (dislocation). The severity of hip dysplasia is rated according to the extent of contact between the femoral head and the acetabulum and signs of osteoarthritis as viewed on x-ray. Although hip dysplasia is typically first recognized in infants, mild hip dysplasia may not be diagnosed until adulthood. Hip dysplasia is a common cause of hip pain in young adults and, if left untreated, can lead to early degenerative changes (osteoarthritis) of the hip joint. Hip dysplasia is a cause of degenerative changes in the hip leading to hip replacement surgery in adults (Millis).

Incidence and Prevalence: Developmental hip dysplasia is present in 100 per 100,000 individuals (McCarthy) and is bilateral in up to 33% of cases (Manaster). In one study, 43% of individuals with hip osteoarthritis also had hip dysplasia (Kim).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Individuals at increased risk for hip dysplasia are those of Native American or Lapp (people indigenous to northern Scandinavia) descent; those of African or Chinese descent have markedly lower risk (McCarthy). There is a strong genetic component; individuals with a family history of developmental hip dysplasia are 10 times more likely to experience the condition than those without (McCarthy).

The risk is highest in females, first-born children, those born in a breech position, and in those experiencing fetal intrauterine crowding or malpositioning. Up to 85% of congenital hip dysplasia occurs in girls (Tham). The left hip is most commonly affected, secondary to the increased incidence of intrauterine positioning in which the left hip of the fetus is compressed against the mother's sacrum (McCarthy).

Individuals with neuromuscular disorders (e.g., cerebral palsy, arthrogryposis, myelomeningocele), those with connective tissue disorders of ligamentous laxity (e.g., Ehlers-Danlos syndrome), and those with scoliosis or torticollis are also at increased risk (Manaster).

Source: Medical Disability Advisor



Diagnosis

History: The individual may report a gradual (insidious) onset of hip and/or groin pain that may radiate into the thigh or buttocks and may report instances of catching or locking sensations in the hip joint with movement. There may be pain at the outer (lateral) hip from muscle fatigue that worsens toward the end of the day or after prolonged sitting or walking, particularly on hilly terrain. The individual may report a history of hip problems and previous non-operative interventions such as being double-diapered or wearing a brace during infancy to help correct congenital hip dysplasia.

Physical exam: Upon exam, range of motion testing generally is normal, although the involved hip may be stiff with attempted movement into abduction and extension due to tight adductor and hip flexor muscles or if severe hip joint subluxation is present. As the hip develops degenerative changes, internal rotation becomes progressively decreased. Leg lengths may be unequal if the hip is fully dislocated, or if growth of the proximal femur was retarded in childhood. Stress tests of the hip joint may reveal instability or clicking of the hip joint. Strength testing of the involved limb may reveal pain and weakness with resisted hip abduction. The individual may exhibit a limping gait pattern in which the pelvis drops toward the unaffected side when weight bearing on the affected limb (Trendelenburg gait pattern); alternatively, the trunk may lurch toward the affected side (abductor lurch) when the affected limb is in the stance phase of gait.

Tests: Abnormalities of the hip joint may be viewed on x-rays taken in a neutral standing (weight bearing) position; in a "false profile" view, in which the individual stands at an angle to the imaging plate; and also in a position of abduction and internal rotation (AIR) to assess alignment of the femoral head within the acetabulum (Sucato). Ultrasound scanning is commonly used in assessment of the infant hip, but is less commonly used for adult diagnosis. Rarely, computed tomography (CT) scan and magnetic resonance imaging (MRI) may be done to rule out potential tears of the cartilaginous ring that surrounds the acetabulum (acetabular labrum), other cartilage defects, and other soft tissue disorders that may exist concurrently with hip dysplasia.

Source: Medical Disability Advisor



Treatment

In infants, hip dysplasia is treated with external bracing (e.g., Pavlik harness) to hold the hips in flexion and mild abduction and external rotation to allow normal development of the hip joint capsule and deepening of the acetabulum. When hip dysplasia is diagnosed during the neonatal period, the harness usually is worn all day and night during about 6 weeks until stabilization of the hip, followed by another 6 weeks of weaning. When treatment is started later or when the hips are more unstable, a longer period of use of the harness may be necessary. Mild cases may be treated by “double diapering” to keep the lower extremities in an abducted position.

In adults with mild symptoms, conservative treatment is indicated using nonsteroidal anti-inflammatory drugs (NSAIDs), activity modification to reduce compression of the hip joint (e.g., minimize prolonged standing and walking), and implementing joint protection strategies to prolong the longevity of the hip joint. A cane in the contralateral hand may decrease pain and decrease the magnitude of the limp. Individuals who are overweight or obese are encouraged to lose weight to decrease the loading forces on the hip joint.

In some cases of mild to moderate hip dysplasia, arthroscopic surgery may be performed to “clean out” the hip joint by removing loose cartilage fragments, débriding a torn acetabular labrum, or removing portions of inflamed synovial tissues. With older children and younger adults with severe hip dysplasia, surgery to realign the hip joint (proximal femoral osteotomy and/or peri-acetabular osteotomy) may be necessary to restore congruence of the joint surfaces, preserve the hip joint, and reduce hip pain. With proximal femoral osteotomy, the surgeon cuts through the top of the femur and repositions it to improve the biomechanical alignment of the femoral head with the acetabulum, securing the femur in place with plates and screws. With peri-acetabular osteotomy, the surgeon cuts the acetabulum away from the pelvis and rotates it into a new position to better hold the femoral head. Tendon release of tight hip flexor and adductor muscles also may be necessary (Manaster). Older individuals and those with severe hip dysplasia with concurrent moderate to severe osteoarthritis may need to undergo hip replacement surgery (total hip arthroplasty).

Source: Medical Disability Advisor



Prognosis

Untreated symptomatic hip dysplasia can lead to impaired joint mobility, chronic pain, and early hip osteoarthritis, which often occurs by the age of 30 to 40 (Millis). Aging and hip dysplasia are significant risk factors for hip osteoarthritis (Jacobsen). Regardless of gender, individuals with hip dysplasia who are obese are more likely to require a total hip arthroplasty than those of normal weight (Jacobsen).

Source: Medical Disability Advisor



Rehabilitation

The focus of rehabilitation for hip dysplasia is to reduce direct weight-bearing forces on the hip, stretch tight musculature, strengthen surrounding hip and trunk musculature to enable a normal gait pattern, and educate individuals to modify functional activities in order to reduce pressure on the hip joint.

Stretching exercises may focus on tight inner thigh (adductor) muscles and hip flexors, while strengthening exercises typically target the gluteals, abductors, and hamstrings to increase muscular support around the painful joint. Low impact activities such as swimming and bicycling are encouraged for overall conditioning. Gait training with an assistive device (e.g., cane, crutch) may be necessary to temporarily reduce the amount of loading on the affected hip. The physical therapist instructs the individual in a comprehensive home exercise program that includes joint protection strategies and strengthening exercises to be performed within pain free range of motion.

Following osteotomy surgery for hip dysplasia, the individual may be hospitalized for 2 to 3 days, after which time inpatient rehabilitation may be necessary; the first goal of rehabilitation is independent ambulation. During recovery, the individual will need modifications and assistive devices to allow for partial weight bearing while the surgical site heals. Gait training with an assistive device will be necessary, with partial weight bearing as indicated by the physician. If, at the beginning, pain is an issue, modalities such as heat and cold may be used. The next goal is to restore motion and strength to the involved hip, following treatment protocols as determined by the surgeon. As strength returns and weight-bearing status allows, the individual transitions to performing independent functional activities without an assistive device and initiates balance and proprioception exercises. A home exercise program should be taught to complement supervised rehabilitation and to be continued after the completion of physical therapy.

Source: Medical Disability Advisor



Complications

Longstanding hip dysplasia may result in the early onset of hip osteoarthritis, formation of bone spurs (osteophytes), and damage to hip soft tissues (e.g., labral tears). Following surgical correction (osteotomy), individuals are vulnerable to complications of anesthesia or of wound healing, transient nerve injury, bone death (osteonecrosis) of the femoral head, repeat hip subluxation or dislocation, bony nonunion, deep vein thrombosis (DVT), and infection.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Prolonged standing and walking may need to be limited. The individual may need to use a cane or crutch when walking to offload the affected joint. Following osteotomy surgery, the individual may be able to return to work after 2 to 3 months according to the surgeon’s recommendations (Peters). Additional time off to attend rehabilitation will be needed after the initial healing phase. If pain medication is needed after return to work, company policy on medication use should be reviewed to determine if such usage is compatible with job safety and function.

Source: Medical Disability Advisor



Regarding diagnosis

Regarding diagnosis:
  • Did individual report a history of hip problems? Previous nonoperative intervention (e.g., being double-diapered or wearing a brace during infancy)?
  • Was hip pain unilateral or bilateral?
  • Was involved hip stiff with attempted movement into abduction and extension from tight adductor and hip flexor muscles?
  • Did individual exhibit a limping gait pattern in which the pelvis drops toward the unaffected side when weight bearing on the affected limb (Trendelenburg gait pattern)? Abductor lurch?
  • Was hip subluxed or dislocated on x-ray? Was hip arthritic on x-ray?
  • Was CT scan or MRI necessary?

Regarding treatment:

  • Is diagnosis of hip dysplasia confirmed?
  • Did individual respond to conservative treatment (NSAIDs, activity modification, joint protection strategies)?
  • If individual is overweight or obese, has individual been counseled to lose weight?
  • Is physical therapy indicated?
  • Is individual’s workplace able to make necessary modifications to restrict prolonged sitting, standing, and walking?
  • Is arthroscopic surgery necessary to “clean out” the hip joint?
  • Was surgery to realign the hip joint (proximal femoral osteotomy and/or peri-acetabular osteotomy) required (usually in childhood)?
  • If individual is older and has moderate to severe hip osteoarthritis with hip dysplasia, is total joint arthroplasty indicated?
  • Is individual compliant with rehabilitation? Home exercise program?

Regarding prognosis:

  • Was moderate to severe hip osteoarthritis present?
  • What type of surgery did individual require (arthroscopic, osteotomy, total hip arthroplasty)?
  • Have modifications been made to the individual’s work environment during recovery?
  • Did adequate time elapse for full recovery?
  • Did individual experience complications that may interfere with a full recovery?

Source: Medical Disability Advisor



References

Cited

Jacobsen, Steffen, and . "Adult Hip Dysplasia and Osteoarthritis: Studies in Radiology and Epidemiology (Abstract) ." Acta Otolaryngol Suppl 77 324 (2006): 1-37. PubMed. 1 Dec. 2009 <PMID: 17380595>.

Kim, Young-Jo. "Nonarthroplasty Hip Surgery for Early Osteoarthritis." Rheumatic Diseases Clinics of North America 34 3 (2008): 803-814. PubMed. 3 Dec. 2009 <PMID: 18687284>.

Manaster, B. J., David A. May, and David G. Disler, eds. "Chapter 44: Congenital and Developmental Hip Disorders." Musculoskeletal Imaging – The Requisites. 3rd ed. Mosby Elsevier, 2006. MD Consult. Elsevier, Inc. <http://www.mdconsult.com/book/player/book.do?method=display&type=bookPage&decorator=header&eid=4-u1.0-B978-0-323-04361-8.50050-5--cesec5&uniq=174181815&isbn=978-0-323-04361-8&sid=925017556#lpState=open&lpTab=contentsTab&content=4-u1.0-B978-0-323-04361-8.50050-5%3Bfrom%3Dtoc%3Btype%3DbookPage%3Bisbn%3D978-0-323-04361-8>.

McCarthy, James J. "Developmental Dysplasia of the Hip." eMedicine. Eds. B. Sonny Bal, et al. 23 Sep. 2009. Medscape. 1 Dec. 2009 <http://emedicine.medscape.com/article/1248135-overview>.

Millis, Michael B., and Stephen B. Murphy. "Chapter 53: Periacetabular Osteotomy." The Adult Hip. Eds. John J. Callaghan, et al. 2nd ed. Lippincott, Williams & Wilkins, 2007. 795-815.

Peters, Christopher L. "Hip Dysplasia and Periacetabular Osteotomy (PAO)." University Orthopaedic Center. 2009. University of Utah Health Care. 3 Dec. 2009 <http://healthcare.utah.edu/orthopaedics/patients/education/hippao.html>.

Sucato, Daniel. "Treatment of Late Dysplasia with Ganz Osteotomy." Orthopedic Clinics of North America 37 2 (1006): 161-171. PubMed. 3 Dec. 2009 <PMID: 16638447>.

Source: Medical Disability Advisor






Feedback
Send us comments, suggestions, corrections, or anything you would like us to hear. If you are not logged in, you must include your email address, in order for us to respond. We cannot, unfortunately, respond to every comment. If you are seeking medical advice, please contact your physician. Thank you!
Send this comment to:
Sales Customer Support Content Development
 
This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is published with the understanding that the author, editors, and publisher are not engaged in rendering medical, legal, accounting or other professional service. If medical, legal, or other expert assistance is required, the service of a competent professional should be sought. We are unable to respond to requests for advice. Any Sales inquiries should include an email address or other means of communication.